Variable speed hydraulic transmission



Feb. 23, 1932. G. E. ZAHN VARIABLE SPEED HYDRAULIC TRANSMISSION Filed Sept. 9, 1929 2 Sheets-Sheet 1 INVENTOR wzyazrmm ATTORNEY Feb. 23, 1932. ZAHN 1,846,932

VARIABLE SPEED HYDRAULIC TRANSMISSION Filed Sept. 9, 1929 2 Sheets-Sheet 2 the driven member is connected with the drive which contacts the cylinder 8, and this flange 5 tion and arrangement of the several parts, to plate 9 is also provided withthe bypass ports Patented Feb. 23, 1932" f s 1,846,932

UNITED (STATES PATENT OFFICE .1

VARIABL SPEED HYDRAULIC TRANSMISSION Application fiIed September 9, 1929. Serial No. 391,263.

Thisinvention relates to a hydraulic vari of the cylinder and'the hubs 3 'formedv'vith able speed power transmission unit which the end plates. These hubsare rotatably armay also'be used as a brake, the general obranged in the bearing members 4. The cylject of the invention being to provide a drive inderl is formed with a bore of two diammember having a ported casing thereon and eters, the large bore being 'eccentrically ar- ,55 a driven member having a casing thereon ranged to provide an eccentric chamber 6. which encloses the first casing, with fluid op- A drive shaft 7 passes through the hub of the erated means carried by one casing and end plate 2 and a casing 8 isffastened to the adapted to engage the other casing whereby shaft and is located within the casing A V the driven me ber will rotate with the drive One end of this casing 8 is closedand its member at the same or any variable speed, other end'is open, with said open end abutaccording to the fluid pressure, with manualting a flanged plate 9 connected with the ly controlled means for controlling "said cylinder 1','with its flange forming a chamber pressure. l 10 between'the' plate'and the end plate 2. A

15 Another object of the invention is to so sleeve 11 is placed in the eccentric part ofthe arrange and construct the parts that a simbore, with one endabutting theplate, 9 and i ple, effective, compact anddurable means of its other end 'abuttingthe. shoulder formed transmitting power from a drivemember to at the junction of the two parts'of'the bore a driven member is secured and one in which Z and this other end has a flange 12 thereon member smoothly and without steps from a is provided with the'byp'as's ports 13'w-hich standing positionto full speed. place the eccentric chamber in communication This invention also consists in certain other with the annular chamber 1 1 formed by the features of construction and in the combinasmall part of the bore and the casingSL The 5 be hereinafter fully described, illustrated in l5 which connect the eccentricchamber with the accompanying drawings and specifically the chamberlO.

pointed out in the appended claims. The casing 8 is provided with the ports116 In describing the invention in detail, ref'erwhich place the interior of the casingin'com- I 5 once will be had to the accompanying drawmunication with the eccentric chamber.

ings'wherein like characters denote like or Arc-shaped wings 17 are each pivotally or corresponding parts throughout the, several hingedly connected at one end to projections views, and in which 18 on the outer circumference of the cylinder Figure 1 1s a view with parts in section, 8, each wing having a beveled free end 19 I 5 this view'showing the bearing members in and the projections 18 form recesses for re- "4o ure 2.

elevation. V c eiving' the wings when said wings are forced Figure 2 is a longitudinal sectional view inwardly by the portions'of the walls of the through the driven and drive members. eccentric chamber which are closest to the, Figure 3 is a section on line 3-3 of Figaxis ofthedevice, as clearly shown in Figure V 5; A tubular valve member 20' is slidably ar- Figure4 is a section on line Hfof Figranged-in the casing 8 and is connected to a ure 2. v rod 21 which passes through a hollow part -Figure 5isa section on line 55 of Figof the shaft 7 by across piece 22 which ure 2. A v I passes through a s10 28 in the shaft 7 so that I 45 Figure 6 is a section on line 6-6 of Figlongitudinal movement of the rod will cause ,95. ure 2. i movement of the valve member,this valve .In these views, A indicates acasing which member being arranged to close or partly constitutes a part of the driven member and close theports 16 when moved in one 'direccomprises the cylinder 1, the end plates 2 tion by the rod. .ln the casing 8 are ports 24,

- which are suitably connected with the ends these serving as by-passes from certain por- I the same when covered by the valve and I parts of a ring 26 on JLi it U

- 3 and the shaft 7 also portions of this chamber with spaces between the chambers 8 and A.

The outer end of the rod 21 is provided with a circular head 25 which is engaged by the hub of the end plate 2, and this ring is operable by shifting lever (not shown) so that the rod 21 and the valve member 20 can be shifted by the manipulation of this lever without interfering with the rotary movement of the parts. Bearing members 28 are arranged between the-hubs associated with each hub for 1 preventing leakage of the fluid in the device around the shaft; 7. A packing. gland 30 is also arranged in the shaft [for preventing leakage around the rod 21. I I

From the foregoing, it will be seen that when theshaft T also be rotated and the walls of the eccentric chamber will cause these Wings to move into and out of the recesses between the projections 18 as the casing 8;rotates. If the ports l6are open, thewings will have free movement as the fluid can; pass from the closing side to the openingside without interfering with the movement of the wings. Thus the casing-A and the parts attached thereto will remain stationary-. as the casing 8 rotates therein. However, ifthe valve member 20 is moved to. a. position to entirely close the ports 16, the fluid is trapped in the eccentric chamber and the wingscannot move inwardly so that the casing A is locked to the casing 8 and therefore must rotatewith said; casing so that the driven member will rotate at the same speed as the drive member. When the valve member 20 is moved to a position to but partly close the ports,a certain-amount of slippage will take place so that the driven member will rotate at a less speed than the drive member and this speed can be adjusted to any desired ratio by the proper adjustment Of the valve member 20 over: the ports 16. As will'be seen, the bypasses 18 and 15 connect the eccentric chamber with the chambers 10 and 14 and any excess pressure on the packingglands, caused by leakage past the bearing'surfaces on the closing side,.is relieved .y passing through the chambers and ports back into the eccentric chamber on the opening side. The bypasses 24 insure a supplyof liquid under the wings as the closing'action begins. I I

The purpose of these ports 13 and 15 is to allow any naturalleakage past the. wearing sur aces of the closing or pressure side to get back into the opening side without building up pressure between the two casings 1 and 8-,which pressure would be exerted against the packing glands. I I Another purpose of these ports 13 and 15 is tov allow any fluid pumped into the space be- .is free, regardless and a packing gland 29 is.

is rotated, the casing 8 will casings, a valve tween the two casings 1 and 8 to get into the eccentric chamber on the opening side.

Any fluid within the casing 1, except that in the closing side of the eccentric chamber of the position of the valve 20, to enter the opening side.

While, the valve 20 shuts off the ports 24 in. one position of the valve, this does not affeet the action of the unit, because whenthe valve is across the ports 24, the ports 16 are open on both the opening and closing sides and the fluid is free to flow directlyacross from-the closing-side to the opening side. The ports 24 could be through the'end wall of casing 8 and function just as well as in the position they are shown. Their only purpose is to allow freedom for-the fluid within the casing 8 to get into the opening side of the eccentric chamber through the chamber 14 and the ports 13. i I

The'construction and arrangement of the partsthus gives all the fluid, within the cylinder 1 (except that in the closing side) freedom to get under the wings on ,the opening side, regardless of the position of thevalve 99 20. On the closing side, all the fluid is trapped there, except as released through the ports 16by valve 20. I I I It is thought from the foregoing description that theadvantagesand novel features of the invention will be readily apparent.

It is to be understood thatchanges may be made in the construction and in the combina-- tion and. arrangement of the several parts,

fall within the provided that such changes I scope of theappended claims.

What I claim is V r 1. A device of the class described comprising a drive member including a casing, a driven member including a casing surroundng the first casing, said second casing having an eccentric chamber therein, the-first casing having portstherein placingthe-interior thereof in communication with the eccentric chamber, fluidpressure operated means carried by the first casing and adapted to contact the walls of the eccentric chamber, fluid in the casings, a valve member for controlling the ports, bypass means connecting portions of the eccentric chamber with 11 other portions thereof and portionsof the eccentric chamber with a space between the two casings.

o 2. A device of the class described comprising a drive member including a casing, a 12 driven member including. a .casing surrounding the first casing, said second casing havingan eccentric chamber therein, the first casing having ports therein placing the interior thereof in communication with the eccentric chamber, fluid pressure operated means comprising pivoted wings carried by the first casing and adapted to contact the walls of the eccentric chamber, fluid in the member for controlling the ports, bypass means connecting portions of, the eccentric chamber with other portions thereof and portions of the eccentric chamber with a space between the two casings, some of the by-pass means being controlled 6 by the valve member. V

3. A device of the class described comprising a drive member including a casing having main ports therein and bypass ports therein, a driven member'including a casing 10 surrounding the first mentioned casing, said 7 second casing having a bore of two diameters, with its large bore eccentric, both portions of the bore being spaced-from the first casing, with the space formed by the small part of the bore communicat ng vwith the bypass ports and the eccentric chamber being in communication with the main ports, wings connected with the first casing and arranged in the eccentric chamber, a ported part separating the eccentric chamber from the concentric chamber, passages connecting portions of the eccentric chamber together and a valve member for controlling the main ports. V

In testimony whereof I aifix my signature.

GEORGE EUGENE ZAHN. 

